Pizza Oven...Fired

So after the last posting I put the oven inside to keep the rain off and allow the clay to begin to dry out. There is a lot of clay with a lot of moisture in it so I gave it several days. Once the clay was pliable but firm I began scooping the sand out from inside the clay form. This process took a little while and had to be carefully done to prevent damage to the oven itself.




Once the csand was out I began slowly heating the inside of the oven to begin seriously drying the clay. Again I wanted this to be a slow process so as not to crack anything (if the clay dried really quickly and shrank unevenly I worried the big dome would collapse) I couldn't get a fire going using wood because there was so much moisture inside the oven. I used a propane torch on low for several days. This provided a nice distractions from farm and winery chores, "sorry dad I need to go check on the oven", was probably a little overused by the end of the week.



Today it was dry enough to get a wood fire going on its own. I fired the oven for about two hours and go it really hot...probably close to at least 600 degrees F. I think it will get hotter after it finishes drying. There was still quite a bit of moisture in the oven when I was firing it.

Once the oven was up to temp, I swept the floor, pushed the fire to the back of the dome and cooked a pizza. It was a pretty big relief to see the thing work after all that effort. Hopefully this will be a nice addition to the winery.

Wood Fired Pizza Oven Part 3

So I got started on the thermal layer of the oven today. The first step here was to get all the building materials together. I have a spot on the farm that has almost pure clay, which is great. However, as it is a desert, the clay is pretty dry and compacted. As seen below.
My solution involved running over it with a forklift...an elegant solution. Most of my problem solving is in this vein.

What I was left with was a nice crushed clay building material. I mixed this with about twice its weight of sand. Clay expands with water and then shrinks when that water/clay dries. I need to keep the oven from shrinking and cracking...too much. Sand doesn't shrink when it dries out so it is a good choice for blending with clay.

The next step is start packing the mud/clay/sand around the prepared sand form. This is a very slow job. You have to be very careful to not break the sand form, not leave any air pockets, and keep the mud layer about 4 inches wide.

8AM

9:30 AM

10:30AM

10:40 (my arms were getting pretty tired at this point)

11:45 AM

After the form dries ("leather" hard for the potters in the crowd) it will shrink a little bit bit but will firm up quite a bit. After a couple of days I will clean up the door opening and cut a chimney. After that we will fire it up and fire off a couple of pizzas. Just to be sure it works before I make it look pretty.

-Neil

Mobile Wood Fired Pizza Oven part 2

So I did some more work on the oven today. I set the last of bricks into the forklift-able steel base. The last few bricks took quite a bit of convincing to get seated properly. I think that bricks are very secure in there home now though.

The next step was to layout the shape of the oven on the bricks. This is to be a round domed oven. Some pizza ovens use a "barrel" style layout. The is going to be a little more all purpose than that. I marked out the circle for a 42" diameter. This should give us plenty of space for a fire and for multiple pizza's or loaves of bread.



After I had the oven chalked out I began mixing some sand and water together to get a mixture that would hold its own weight. Next a started piling the sand into the marked oven area.




Finally I shaped the sand into a dome. This dome represents the inside of the oven space. The next step will be to pack clay around the outside of the sand form.
So the next step is going to be coming up with a clay mixture to pack around this form. After mixing 10 wheelbarrow loads of sand and water today just to get the form put together I think that I will rent a commercial mixer for the clay work...my back is kind of killing me right now.

Neil

Mobile Wood Fired Pizza Oven

So we have been talking about building a mobile pizza oven to go with our farm's big barbeque for a while now. I built an oven for my house a while ago and love it. It makes for a great day after working at the winery. Go home, have a beer, play with fire for a little while and finally eat pizza. We wanted something like that at the winery but have been going around and around as to how to do it. I finally took the plunge and got started on it this week. I don't really know what I am doing here, but so far so good.

Whats the worst that can happen right?

I am trying to use as much found (not purchased) material as I can for this project. Hopefully all I will need to buy is welding rod and bricks (I have had to buy a couple of pieces of steel that I couldn't pull out of the farm's scrap bin...but hopefully that is the end of purchases!).

I am hoping to get a finished clay oven with a 43" inside cooking surface that we can pick up with a forklift and put on the back of our pig roasting trailer.

The first step was to cut a piece of steel and reinforce it with channel iron.






The next step was to lay another series of channel down for stiffening the frame in the opposite direction and to give us something to get the forklift underneath.

After that we laid out the insulating fire bricks, which are to be the base of the oven. We then welded some angle iron on in order to hold the bricks tightly together on the top of our steel structure. I took this opportunity to shoot a little high temp engine paint on this thing so it wouldn't look quite so "rustic".



The final thing I did today was to add a fine layer of sand as a bed for our fire bricks and start the brick layout. Because our bricks are held together tightly by steel angle iron I figured it would be fine to skip the fancy patterns and just lay them seam to seam. I guess we will see how it works out.
So that is all I have done at the moment. The next step is going to be gathering the clay and mixing it with sand to build the dome. I should be getting going with that in the next couple of days as time allows. Then on to pizza...and more importantly beer! Or wine I guess, if you know where to find any.

-Neil